A. Discussion of the Prior Art
Vacuum cleaners of various types and other waste material collection devices are known in the prior art. These devices generally are of relatively small capacity intended for household use and including the feature of portability, or of very large size intended for industrial use and requiring sophisticated material-handling techniques, or extensive installations for the handling and disposal of waste material collected by the vacuum cleaner and moving said materials to their ultimate disposal point.
One common method used in certain vacuum cleaning devices is to utilize a porous container which serves as both filter and waste collection container. This porous filter container is sealed around the inlet thereto, and a vacuum applied in a chamber behind said filter container and causing the air medium containing the waste particles to move therethrough, resulting in the entrapment of said waste particles in the filter bag. The filter bag element in this application requires its sealing both to the inlet thereto, through which the gaseous medium containing the waste particles can pass, and is further required to be sealed on its exterior portion with the vacuum chamber itself.
The invention is distinguished from this first type of device through its use of an enlarged vacuum chamber of relatively large size compared to the dimensions of the intake pipes, which results in the creation of a relatively high vacuum at the intake end and throughout the length of the intake pipe system, with a corresponding decrease in the velocity of the airflow upon entry into the vacuum chamber, which operates in conjunction with a system of baffles and filters for dry material pickup and a filter system for wet medium pickup, serving to filter out waste material particles prior to entry into the blower intake mounted direcatly behind the filter and baffle system.
A second type of small application vacuum cleaner is of the cannister-type commonly used in small workshops, utilizing a nonpermeable liner which is itself sealed around its opening between the drum of the unit and the topmost plate containing the vacuum machinery. The emptying of said inner container or liner in this application is accomplished by the removal of the entire power and suction unit from the lower drum portion of the device, and the flexible liner removed therefrom. In this device, the flexible liner is of an impermeable material so as to facilitate the collection of the waste material, but must be perforated around its uppermost portion to permit the application of the vacuum in order to cause the gaseous medium containing the waste material in suspension to pass therethrough.
The invention avoids the drawbacks of this second prior art device in that it utilizes a large size framework, custom designed for the task it is expected to perform, rather than the use of light-weight, relatively small and low-powered unit for placement on standard drum containers. Similarly, the invention avoids the use of the liner which must be sealed around the total periphery of the outer container at the juncture with the plate bearing the operating mechanism of the device. Similarly, the internal collection device in the invention can be manufactured to whatever dimensional and structural criteria are suitable to the job, rather than the use of a limited plastic film liner with perforations along its upper periphery. The prior art would obviously be unsuitable for the collection and removal in the inner carrier of heavy or sharp materials.
In the area of industrial vacuum cleaners, both fixedly mounted and mobile types are known. In many applications a centrally located vacuum unit can be connected to various inlet openings located strategically throughout a plant or factory. Whether by use of a pulsating airflow, implosion, or relatively continuous suction, the method of disposal of the waste material from the central location has required the manual unloading of a hopper fixedly mounted with the unit.
In the case of mobile industrial vacuum cleaners, greater flexibility was permitted in the prior art in the unloading of the waste material when compared to that of the fixedly mounted units. Although some mobile industrial vacuum cleaners retain the manual unloading feature through access doors, or the like, the mobility of the unit permitted the movement of the entire vacuum cleaner to a suitable dump site, from which it could then be unloaded. The means of unloading said devices included, in addition to the mere use of access doors, containers which are an integral part of the vacuum system. These containers commonly are pivoted, or hinged, so that they may be disconnected from the housing of the vacuum unit and dumped by pivoting from a substantially vertical position to a position with the opening facing substantially sideward or downward. Other applications use a pivoting to a dumping position following disconnection from the power source and other support machinery. In various applications mobile industrial vacuum cleaners utilize either completely separable components permitting the container to be moved a substantial distance from the main housing, or require that the entire vacuum cleaner unit be moved near the dump site.
To the best of applicant's knowledge, there are no comparable units presently available, nor are there any U.S. or foreign patents disclosing such a unit.